This study assesses the level of background radiation for Sanliurfa province of southeastern Turkey. Measurements of outdoor gamma radiation (of terrestrial and cosmic origin) in air were performed at 112 locations using a plastic scintillator and the average absorbed dose was found as 60.9 nGy/h (corresponding to an effective close of 74.7 mu Sv/y). The radionuclide activity concentrations in 45 soil samples collected from the study area were measured through gamma-ray spectrometry and the average activities were determined as 20.8. 24.95 and 298.6 for the natural radionuclides U-238, Th-232 and K-40, respectively, and 9.08 Bq/kg for the fission product Cs-137. The natural radioactivity sources resulted in an effective dose of 46.9 mu Sv/y. The radioactivity levels of 53 drinking water samples were measured as 0.038 Bq/l for gross-alpha activity and 0.1324 Bq/l for gross-beta activity using gross-alpha and gross-beta counting methods (equivalent to a,in effective dose of 7.76 mu Sv/y). When compared with the data available for other Turkish cities, the outdoor gamma doses and soil radioactivity concentrations obtained in this study indicate a background radiation level that falls within natural limits. Oil the other hand, the measured gross-alpha and -beta activities in drinking water are relatively higher. (c) 2007 Elsevier Ltd. All rights reserved.